Corps of Engineers, The Nature Conservancy Partner to Protect Natural Diversity of the Savannah River Through Strategic Dam Management

Controlled Water Release on Savannah River Planned for March

Savannah, GA—March 7, 2006—Officials with the U. S. Army Corps of Engineers’ Savannah District, in partnership with The Nature Conservancy, announced plans today for a controlled water release on the Savannah River scheduled to begin between March 10 and March 20. The controlled water releases, which began in 2004, are part of the Sustainable Rivers Project, a continuing national partnership between the Corps and The Nature Conservancy to protect the natural diversity of American rivers while continuing to provide critical human services such as flood control and power generation. The U.S. Fish and Wildlife Service and the Georgia and South Carolina Departments of Natural Resources are cooperating with this water release.

During the controlled release, boaters and recreational users downstream of the J. Strom Thurmond Dam are urged to use extreme caution due to stronger river currents.

The controlled releases will last three to five days and result in a daily average flow of at least 23,000 cubic feet per second (cfs) at the New Savannah Bluff Lock and Dam. The timing and the duration of the pulse releases are designed to mimic natural seasonal flooding, which would have occurred before the dams were in place.

"The dams on the Savannah River have altered natural flow patterns, which not only disrupt the riverine habitat for fish and birds, but also impairs the natural ecological functions of the floodplain and estuary, such as providing clean water and nutrients to the estuary that aid in the development of crabs and shrimp," said Amanda Wrona, Ph.D., Savannah River project director for The Nature Conservancy in Georgia. "Through this national partnership with the Corps of Engineers, The Nature Conservancy is working to ensure the needs of Georgians and South Carolinians are met while addressing and reversing the growing environmental impacts to the river caused by dams."

Forming the border between the states of Georgia and South Carolina, the Savannah River supports natural communities such as shoals, floodplain forests and estuaries, as well as numerous rare and endangered species, including the robust redhorse, which was thought to be extinct at one time.

The Benefits of the Water Release
Scientists anticipate the higher flow levels will create conditions suitable for certain fish species to swim beyond the dam to their historic spawning grounds, while minimizing possible conflicts with the spawning period in the lakes. As the Corps of Engineers continues to monitor the water flows from the controlled releases, The Nature Conservancy is working with numerous partners to evaluate the various ecological effects of the releases on the floodplain and estuary.

The Georgia Department of Natural Resources will sample above and below the Lock and Dam to determine the extent to which populations of American shad and striped bass passed beyond the dam due to the increased water flows. The Nature Conservancy, University of Georgia and the South Carolina Department of Natural Resources will conduct a study to test if the federally endangered shortnose sturgeon can pass through the Lock and Dam into their historic spawning grounds.

The University of Georgia and The Nature Conservancy will evaluate the ecological benefits of the water release to fish, invertebrates and the forests of the floodplain, and Savannah State University will monitor the effectiveness of additional levels of freshwater to maintain a healthy salinity balance in the estuary.

Adaptive Management Strategies
In preparation for these controlled releases, the Corps of Engineers, through the use of adaptive management techniques, has stored additional water within the flood control pools at Hartwell and Thurmond Lakes. Each of the three lakes -- Harwell, J. Strom Thurmond and Richard B. Russell -- will drop more than one foot. However, the resulting elevations will remain near the seasonal average.

"These controlled releases will be evaluated on a yearly basis," said Jeanne Hodge, Savannah District spokesperson. "Should conditions change in future years, and there is more precipitation, the lakes will likely be drawn down to their normal winter levels to provide additional flood storage."

The City of Augusta will begin lock operations for fish passage on March 31, rather than March 15 as in previous years, to enable scientists to better evaluate the effectiveness of the controlled release on fish passage. Fish lockage will take place each morning at the New Savannah Bluff Lock and Dam on Mondays, Wednesdays and Fridays from 8:30-9:45 through May 15. This action is expected to pass additional fish upstream to the Augusta Shoals spawning area.